{"id":"CVE-2026-64391","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: use opener credentials for ADS I/O\n\nAlternate data streams are stored as xattrs","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: use opener credentials for ADS I/O\n\nAlternate data streams are stored as xattrs. Unlike regular file I/O,\ntheir read and write paths therefore call VFS xattr hel…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.15, < 6.12.96","linux_kernel >= 6.13, < 6.18.39","linux_kernel >= 6.19, < 7.1.4"],"patched":["linux_kernel 7.1.4"],"published":"2026-07-25","updated":"2026-09-04","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64391","references":[{"url":"https://git.kernel.org/stable/c/2b4592cea214683de0f2ce6f8c22c097fb0ea1ab","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/52a56cf53ec834c44ac1b4d16d585f26613ee5ce","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a8f5d39971bbad9340d49cd41b0e2da9452a649d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/baa5e094886fffa7e6272edcb5e08be5ce28262c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00457,"epssPercentile":0.3899,"ingestedAt":"2026-09-05T13:39:57.480Z","slug":"CVE-2026-64391","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: use opener credentials for ADS I/O\n\nAlternate data streams are stored as xattrs. Unlike regular file I/O,\ntheir read and write paths therefore call VFS xattr helpers which recheck\ninode permissions and LSM policy using the current task credentials.\n\nRun ADS I/O with the credentials captured when the SMB handle was opened.\n\n## Affected\n\n- `linux_kernel >= 5.15, < 6.12.96`\n- `linux_kernel >= 6.13, < 6.18.39`\n- `linux_kernel >= 6.19, < 7.1.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.1.4`","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}